1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device, and a semiconductor device manufactured by applying the method. In particular, the present invention relates to a manufacturing method of a semiconductor device by peeling off a transistor from a substrate with use of a peeling layer made of stacked layers of a metal film and a metal oxide film that are provided between the substrate and the transistor.
In this specification, a semiconductor device includes, in its category, an RFID (Radio Frequency Identification) tag, a memory, an integrated circuit, a CPU (Central Processing Unit), a microprocessor, and the other component or product. Note that an RFID tag is also referred to as a wireless IC tag.
2. Description of the Related Art
In recent years, the necessity of an RFID tag has been increased in any field that requires automatic identification such as management of products. In general, an RFID tag is a compact device provided with an antenna for wireless communication and a compact IC chip. The IC chip is formed of an integrated circuit having a transistor provided over a silicon wafer, and the like.
In recent years, various techniques such as a method of removing a substrate by grinding, polishing, or dissolving and a method of separating a transistor provided over a substrate from the substrate are considered for further reduction in cost and film thickness of an RFID tag. As a method of peeling off a thin film transistor provided over a substrate, for example, there is a technique by which a thin film transistor is provided over a substrate with a separating layer made of amorphous silicon interposed therebetween, and hydrogen contained in the amorphous silicon which is a separating layer is released by irradiating with a laser beam which is transmitted through the substrate from the substrate side, thereby separating the thin film transistor from the substrate (see Japanese Patent Application Laid-Open No. 10-125931)
However, the method of removing a substrate by grinding, polishing, or dissolving causes problems: a damage due to physical force such as stress, contamination, and the like. Further, in the case of employing the method of peeling off a thin film transistor by laser beam irradiation, it is necessary to use a substrate having high light transmissivity, and entire irradiation with a laser beam having relatively high energy is required to provide energy enough to make the laser beam pass through the substrate and release hydrogen contained in amorphous silicon. Therefore, it is a problem that a layer to be peeled is damaged. According to such methods, it is quite difficult to reuse a substrate and the cost is increased.